Skip to main content

Full text of "Flora Indica Vol-I"

See other formats

Memspermacea.l                 FLORA INDICA.                                   171
between Menispermaceoi and the Orders just mentioned, it cannot be denied that the
large size of the embryo, and the small quantity of albumen, are very abnormal in
the class to which they belong, and indicate that their true position is at one extre-
mity of this class, and that, as in the case of Dilleniacea, they form a passage from
it to another part of the vegetable kingdom. In fact, we think that the relationship
of Menispermacea to the Malval alliance, in which we include JSuphorbiacea, is un-
mistakable. A. St.- Hilaire has already indicated the resemblance in the androBcium
to Phyllanthus, and indicated the connection which is established between Meni-
gpermacea and Malvacea by means of JSuphorbiacea'; and De Candolle has noticed
an approach in the same parts to Sterculiacea.
The relationship which exists between Menispermacea and EuphorUacea appears
to us to be too close to be merely regarded as one of analogy. We do not attach
much weight to the uniscxuality of both Orders, nor can we adduce the scandent
habit of Flukenetia, Dalechampia, Pterococcws, Tragia, and other ISuphor&iaceeS, as
a very important resemblance. The peltate leaves of species of Mappa, Jatropha,
and many other Euphorbiacee8> and the pseudo-articulation of the leaves of dcca,
Conceveiba, Cleidion^ and others, may also be regarded as distant resemblances. It
is the close agreement in structure both of the male and female flowers of many of the
trimerous genera of Eaphorbiacea to those of Me9iispermacfea which we are disposed
to regard as important. The stamens of Hktphorfoacea are so often identical with those
of MenispermacecB, that it is needless to enumerate instances, which.«ccur as well
among the genera with free stamens as among those in which the stamina are united
into a central column. The ovaries of the two Orders, again, are in many instances
undistinguishable, except by their being united in the one and free in the other; and
the mode of division of the styles of JEuphorfiiacete is repeated in some genera of
Meni$permace<e. If to this we add the Euphorbiaceoua male flower of Mr. Miers*
genus Odontocarya, the peltate ovules of Glochidi&n and allied genera, the loculi-
cidal dehiscence of the putamen, which is always more or less evidently present in
Menispermace<8> the frequently curved* embryo of J&upforbiacea, and the peculiar
structure of the cocci of Phyllantkvs, a* figured by Jussieu, with cavities like those
so characteristic of 3fe*i#permacea, we have a aeries of resemblances which cannot
be neglected.
In the structure of their stems Meni#permace<s almost invariably depart from the
(Ordinary type of exogenous vegetation, and there are few or no natural orders of
Dicotyledonous plants of equal number of species in which this departure is so great
and so uniform.
The greatest differences of opinion have existed amongst botanists as to the value
of the characters derived from a study of the vegetative organs, and especially the
axis of Exogens, in a systematic and physiological point of viewj the more theoretical
observers have predicted far too much from the inquiry, the purely systematical have
coo often neglected it. Those who have combined a sufficiently extensive knowledge
of systematic and-physiological botany hare for the most part considered the struc-
ture of the wood to be of very subordinate value: we ourselves adopt this view,
from the writings of Brown, Adrien de Jussieu, and Decaiane, with whose observa-
tions our experience entirely coincides; and we would (with Decaisne) recommend a
careful study of Menispermacete, and a comparison of the woods of the different genera
one with another, and with other plants, as strongly corroborative of this opinion.
In a systematic point of view, however, the wood often becomes a safe guide to the
affinities of a plant when the organs of vegetation and reproduction are arrested in
development, or defeat our attempts at analysis; on the other hand, in a physiological
point of view, the structure of the1 common axis rather tends to confound our pre-
conceived ideas of the necessary adaptation of structures to particular functioas, and
of these functions being indicated by structure. Without presuming to say that
no relation exists between the habit of plants and their wood, or their wood and
floral organs, we may affirm that we have never been able to detect any, though we
have studied the subject in the forests of the most favourable localities. One broad
fact has indeed been generally recognized, that most climbing plants have abnormal